1. Field of the Invention
The present invention relates to a field of communication and more particularly to multi-media conferencing between UPnP enabled telephony devices and WAN devices.
2. Description of the Related Art
Universal Plug and Play (UPnP) is a set of computer network protocols promulgated by the UPnP Forum. The goals of UPnP forum are to allow devices to connect seamlessly and to simplify implementation of networks in home data sharing, communications, and entertainment and corporate environments. UPnP achieves this by defining and publishing UPnP device control protocols built upon open, Internet-based communication standards.
The UPnP architecture allows peer-to-peer networking of personal computers (PCs), networked appliances, and wireless devices. It is a distributed, open architecture based on established standards (e.g., UPnP telephony device/IP, UDP, HTTP and XML). The UPnP architecture supports zero-configuration networking. An UPnP compatible device from any vendor can dynamically join a network, obtain an IP address, announce its name, convey its capabilities upon request, and learn regarding presence and capabilities of other devices.
Similarly, UPnP devices can leave the network automatically without providing any unwanted state information. UPnP protocol provides discovery, control and eventing mechanisms. Discovery is enabled using Simple Service Delivery (SSD) protocol. All control messages are in the form of extended markup language (XML). Eventing follows General Event Notification Architecture (GENA) protocol. Using these technologies, UPnP makes availability and unavailability of the UPnP devices on the fly to the other devices in the network.
The UPnP forum also provides telephony services for extending user experience in a home to access telephony services like messaging service, presence service, and Call handling (PS/CS call) service. As analogous to UPnP DA, telephony defines three kinds of devices, viz. a telephony server (TS) that provides messaging, and presence related services to the user, a telephony control point (UPnP telephony device) to initiate actions provided by the TS and a telephony client device (TC) for media related handling and providing input and output to/from the TS.
The UPnP telephony services enables a user to initiate a call to any user outside the UPnP network using a wide area network (WAN) calling technology like VOIP or other calling technologies. However, the UPnP telephony service allows the user to initiate the call with a single WAN device and not a conference call media session with two or more WAN users as the UPnP telephony network may not support all types of media content. For example, a television set can display a plain text and may not support video. In case, video frames need to be retrieved, media negotiation has to be carried out prior to performing setting up the multi-media conferencing session. Additionally, the WAN devices are unaware of the media capabilities of the UPnP telephony device or TC.
If the media capabilities, such as supported multipurpose internet mail extensions (MIME) types, are not considered, then it is possible that the UPnP telephony device may receive unsupported media content from the WAN devices (not at all supported by the UPnP telephony device) in the conference call media session, resulting in inconsistent user experience with respect to the conference call media session. Currently, the UPnP telephony service fails to capture and provide dynamic session information (e.g., the user leaving or joining the session) associated with the conference call media session as dynamic information is required to be pushed to the user rather than pulled from the UPnP telephony device.